Stoker mechanism



June 20, 1939;,

R. E. BRESSLER STOKER MECHANISM Filed Feb. 13; 2937 2 Sheets-Sheet lJune 1939- R. E. BRESSLER mm rmcmmxsu 2 Sheets-Sheet 2 Filed Feb. 13,1937 Patented June 1939 P TENT OFFICE STOKER MECHANISM Robert E.Bressler, Oregon, 111., assignor to Kol- Master Corporation, Oregon,111., a corporation of Illinois Application February 13, 1937, SerialNo. 125,583

2 Claims.

This invention relates to improvements 'in stoker mechanism, and itconsists of the matters hereinafter described and more particularlypointed out in the appended claims. The present invention relates moreparticularly -to the means for feeding solid fuel from the fuel hopperto the feed screw duct for conveying the solid fuel to the retort.

In my prior Patent No. 1,956,789 granted May 1, 1934, is shown astructure for a similar purpose wherein the disk at the bottom of thehopper has peripheral teeth meshing with the helical blade or flight ofthe feed screw so as to be rotated or driven thereby, the presentinvention being an improvement thereon.

One of the objects of the present invention is to provide meansindependent of the feed screw which will insure a positive feed of solidfuel from the fuel hopper to the screw conveyor duct and at the sametime eliminate arching or packing of the fuel in the hopper in thevicinity of its outlet end where it communicates with the duct.

A further object of the invention is to provide a mechanism for feedingsolid fuel from the '25 hopper to the conveyor duct, the parts being soarranged as to insure a substantial filling of the v duct and to causeless wear on the parts involved, so that the mechanism will have alonger period of usefulness without requiring service attention. I

The above mentioned objects of the invention, as well as others,together with the several advantages thereof .will more fully appear asI proceed with my specification. i

In the drawings: 2 Fig. 1 is a perspective view of an underfeed stokerembodying the preferred form of the invention. Fig. 2 is a plan view ofthe drive box end of the conveyor duct and associated parts with thehopper removed from its bottom better to show the structure involved.

Fig. 3 is a detail vertical sectional view through apart of the hopperbottom and drive box on an enlarged scale as taken on the'line 33 ofFig. 2.

Fig. 4 is a detail the drive box of the stoker mechanism as taken on theline 4-4 of Fig. 3. r

Fig. 5 is a view similar to Fig. 2 illustrating a modified form of theinvention and which will be more fully referred to later. I

Referring now in detail to Lthat embodiment of the'invention illustratedin the drawings: ID indicates the retort or tuyere basinof the stokervertical sectional view through and H indicates a section of a fuel tubeor duct. Said tube or duct opens at one end into the bottom of theretort at one end thereof and it is through this tube that solid fuel isfed to the fuel bed in the retort from below. The other end of saidsection II is operatively connected to one end of a second section l2 ofthe duct, the other, end of said section l2 being closed but operativelyconnected to a driving gear containing box. structure l3. In thesections II and I2 is a means for conveying fuel through the tube to theretort and as herein shown, said means constitutes ascrew l4 which isdriven by means shortly to be described. l5, as a whole, indicates ahopper for solid fuel. This hopper is offset laterally with respect tothe tube section l2 and its bottom l6 may form an integral part of thattube section. As herein shown, the hopper bottom I6 is rectangular andcommunicates with one side of the tube section l2 which mayhave a topopening I! therein at this point. A removable cover plate l8 (see Fig.l) is. provided for said opening, whereby access may be had to the feedtube or duct for the re.- moval of such obstructions as may here occur.

The outer end of the feed screw It extends to or toward the drive box l3and is there operatively connected to a shaft on which is mounted aratchet wheel l9. At proper intervals this ratchet wheel is. rotatedstep by step, whereby the feed screw is actuated to convey the solidfuel fed .thereinto from the hopper, to the retort. For actuatingsaid'wheel l9, the following-mechanism is provided. On one end of thebox I3 is Q mounted amotor 20 operatively connected to one 5 end of ahorizontal shaft 2| located :in the top portion of the box and at aright angle to the axis of the 'screw- 1!. This shaft is 'journalled insuitable bearings 'provided therefor in the feed box and on said shaftis secured a worm 22. Said worm meshes witha worm gear 23 on ahorizontal shaft 24 arranged transversely of and journalled in oppositewalls of the box l3. The shaft 24 is provided with an eccentric 25 uponwhich" one end of a pair of connecting rods 26 is operatively engaged.The other ends of said rodsare connected to assoclatedarms 21 pivotedcoa xiallywith respect to the axis of the ratchet'wheel l9. On each armiscarried a pawl 28 for engage- 5o ment with the teeth of said ratchetwheel. Thus, in the rotation of the worm gear 23, the arms 21 are rockedback and forth to turn the ratchet wheel l9 and the feed screw l4 stepby step.

A holding pawl 29 is provided in the box I; to

hold the ratchet wheel against retrograde movement.

The other end of the shaft 2| projects through the associated wall ofthe box l3 and a fan or impeller of a blower 30 is fixed thereto. Thedischarge end of the blower is connected to an air duct 3| associatedwith the retort I0 whereby air to support combustion is delivered to thewind box Ma and thence through tuyeres 31b to the fuel bed in saidretort.

In the bottom I6 of the hopper is located a circular feeding disk orplate 32 of such a diameter as to be out of all engagement with the feedscrew l4. 'Ihis'disk is provided with a central hub 33 fixed to the topend of an upright shaft 34 journalled in and extending downwardlythrough the bottom wall of the hopper, as shown in Fig. 3; The disk, asshown in Fig. 2 is provided with a plurality of radial ribs 35 whichtaper in height from the hub toward the periphery of the feeding disk.This feeding disk is driven concurrently with, but independent of, thefeed screw and operates to move suflicient solid fuel toward the outletof the hopper bottom into the conveyor tube, and at the same time causea circular movement of the fuel in the bottom of thehopper to preventits arching and packing. 4

As shown in Figs. 2 and 3, the feeding disk is driven from the box l3 asfollows." Below and at one side of the plane of the shaft 24, is locatedanother horizontal shaft 36. One end of this shaft is journalled in oneside wall of the feed box and on said end, within the box, is secured asprocket wheel 31. A chain 38 is trained about said sprocket and over acompanion sprocket 39 on the shaft 24. The other end of the shaft 36extends under the bottom of the hopper, radially of the shaft 34 thereinand is Journalled in a bracket 40 depending from said hopper bottom.Coacting bevel gearsJl-fl are secured to said shaft ends as best shownin Fig. 3.

It is apparent that with the structure described, both the feed screw l4and the feed disk 32 in the hopper bottom are driven from the feed boxat the proper speed ratio. As the disk 32 is in no manner directlyengaged with the helical rib or flight of the feed screw, a betterfeeding of solid fuel is possible because of a more unobstructed outletfrom the hopper into the conveyor tube. Also, wear on the feed screw andfeed disk is reduced. By such a driving arrangement it is possible tomove the feed disk at such speed that the feed screw' conduit can bemaintained substantially full of fuel at all times that there is fuel inthe hopper.

In Fig. 5, I have showna modified form of the invention wherein thefeeding disk in the fuel hopper is driven independently of not only thefeeding disk, instead of being radial with respect.

to the axis of the feeding disk, may be tangential to the hub, as shown.This arrangement provides a better feeding action of the fuel from thehopper out through the outlet of the hopper bottom into the conveyortuba-as a more direct "push is given to the fuel in its movement fromthe hopper bottom into the conveyor tube. When an independent motor isemployed for driving the hopper feed, the motor may be controlled in anydesired manner, to be energized and deenergiz'ed with the motor which,of course, would then only drive the feed screw and the blower.

As the feeding disk is driven independently of and is in no mannerengaged with the feed screw; the wear on the disk and feed screw'respectively is reduced to a minimum. Also, because of the omission ofthe interengagement of the teeth of the feed disk with the threads ofthe feed screw, the coal may flow or move with greater freedom into thefeed screw conduit.

While in describing the invention, I have referred in detail to theform, arrangementand construction of the parts thereof, the same is .tobe considered only in the illustrative sense so that I do not wish to belimited thereto except as may be specifically set forth in the appendedclaims.

I claim as my invention: a

1. In a fuel feeding mechanism, a fuel duct, a fuel hopper arranged toone side of said duct and having a bottom with an outlet openinglaterally into the duct, means in the duct for moving fuel therethrough,and a rotative feeding disk in the bottom of said hopper having aplurality of fuel feeding ribs engaged with the fuel in said bottom ofthe hopper for feeding fuel through the outlet into the duct, said ribsbeing arranged other than radial to the axis of the-disk.

'2. In a fuel feeding mechanism, a fuel duct, a fuel hopper arranged toone side of the duct and having a bottom with an outlet openinglaterally,

ROBERT E. BRESSLER.

